backtrace.c

/* Return backtrace of current program state. Generic version. Copyright (C) 1998, 2000, 2002, 2004, 2005 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */#include <execinfo.h>#include <signal.h>#include <frame.h>#include <sigcontextinfo.h>#include <bp-checks.h>#include <ldsodefs.h>/* This implementation assumes a stack layout that matches the defaults used by gcc's `__builtin_frame_address' and `__builtin_return_address' (FP is the frame pointer register): +-----------------+ +-----------------+ FP -> | previous FP --------> | previous FP ------>... | | | | | return address | | return address | +-----------------+ +-----------------+ *//* Get some notion of the current stack. Need not be exactly the top of the stack, just something somewhere in the current frame. */#ifndef CURRENT_STACK_FRAME# define CURRENT_STACK_FRAME ({ char __csf; &__csf; })#endif/* By default we assume that the stack grows downward. */#ifndef INNER_THAN# define INNER_THAN <#endif/* By default assume the `next' pointer in struct layout points to the next struct layout. */#ifndef ADVANCE_STACK_FRAME# define ADVANCE_STACK_FRAME(next) BOUNDED_1 ((struct layout *) (next))#endif/* By default, the frame pointer is just what we get from gcc. */#ifndef FIRST_FRAME_POINTER# define FIRST_FRAME_POINTER __builtin_frame_address (0)#endifint
__backtrace (array, size)
void **array;
int size;
{
struct layout *current;
void *__unbounded top_frame;
void *__unbounded top_stack;
int cnt = 0;
top_frame = FIRST_FRAME_POINTER;
top_stack = CURRENT_STACK_FRAME;
/* We skip the call to this function, it makes no sense to record it. */
current = BOUNDED_1 ((struct layout *) top_frame);
while (cnt < size)
{
if ((void *) current INNER_THAN top_stack
|| !((void *) current INNER_THAN __libc_stack_end))
/* This means the address is out of range. Note that for the toplevel we see a frame pointer with value NULL which clearly is out of range. */break;
array[cnt++] = current->return_address;
current = ADVANCE_STACK_FRAME (current->next);
}
return cnt;
}
weak_alias (__backtrace, backtrace)
libc_hidden_def (__backtrace)